From: Loup Vaillant <loup@loup-vaillant.fr>
Date: Sat, 24 Feb 2018 14:46:49 +0000 (+0100)
Subject: Strength reduction for Chacha20
X-Git-Url: https://git.codecow.com/?a=commitdiff_plain;h=c08d3c300b11adc9ac02d90e59c7306ea6c0bcd3;p=Monocypher.git

Strength reduction for Chacha20

The performance gain is tiny, but measurable.
---

diff --git a/src/monocypher.c b/src/monocypher.c
index 5fee4de..a792b38 100644
--- a/src/monocypher.c
+++ b/src/monocypher.c
@@ -236,15 +236,16 @@ void crypto_chacha20_encrypt(crypto_chacha_ctx *ctx,
         if (plain_text != 0) {
             FOR (j, 0, 16) {
                 u32 plain = load32_le(plain_text);
-                store32_le(cipher_text + j * 4, ctx->pool[j] ^ plain);
-                plain_text += 4;
+                store32_le(cipher_text, ctx->pool[j] ^ plain);
+                plain_text  += 4;
+                cipher_text += 4;
             }
         } else {
             FOR (j, 0, 16) {
-                store32_le(cipher_text + j * 4, ctx->pool[j]);
+                store32_le(cipher_text, ctx->pool[j]);
+                cipher_text += 4;
             }
         }
-        cipher_text += 64;
         ctx->pool_idx = 64;
     }